Lens attachment for flash-light photographing

ABSTRACT

In an automatic flash camera having a lens with a rotatable focusing ring, a lens attachment coacts with the focusing ring to control the camera. In the attachment, a mounting arrangement detachably mounts the attachment to the end of the lens. An interconnecting arrangement, rotatably mounted on the mounting arrangement, engages the focusing ring to move therewith. A variable resistance system is mounted on the two arrangements and is varied by movement of the interconnecting arrangement relative to the mounting arrangement. The variable resistance system includes an adjustable member which is movable between a number of positions. In one position the variable resistance system exhibits one range of resistances corresponding to one type of lens when the interconnecting arrangement is moved. In other positions the variable resistance system exhibits other ranges of resistances each corresponding to lenses of other aperture ratios and focal lengths. An electrical system connected to the variable resistance system responds to the value of the resistance exhibited and controls the diaphragm of the camera for automatic flashlight photography.

The present invention relates to a lens attachment for flash-lightphotographing, and particularly, a lens attachment for flash-lightphotographing, which is additionally fitted to a photographic lens forautomatic flash-light photographing.

In case of flash-light photographing, such an auxiliary light means as aflash bulb, a strobo lamp or the like is made flash synchronously withthe operation of a camera shutter to illuminate the object to besnapped, so that a good exposure can be obtained even for the darkobject to be snapped in flash-light photographing. In such case offlash-light photograhing, the quantity of light to be obtained byflashing of such as a strobo bulb, used for an auxiliary illuminationlight, namely the guide number has various values, so that each time ofphotographing it becomes necessary on the camera side to calculate thenumber GN and the distance D to the object to be snapped in order to getthe diaphragm F = GN/D.

It is very troublesome to calculate as above each time a photograph istaken. Therefore, as a method to get rid of this defect, it has hithertobeen suggested that as shown in for example U.S. Pat. Nos. 3,074,331,3,128,168, 3,134,315, 3,169,464, 3,198,096, 3,102,461, BP 920,826, U.S.Pat. Nos. 3,084,605, 3,087,397, BP 984,435, DP 1,170,774, FP 1,340,577,U.S. Pat. No. 3,075,442, DP 1,173,334, a mechanical calculationmechanism is equipped inside a camera or a lens tube and is soconstructed as to figure out the diaphragm value or the distance valuefor a good exposure when the distance or the diaphragm is adjusted byadjustment of the guide number. It is well-known as another suggestionto be enumerated that as shown in for example Japanese PatentPublication No. Sho-3-9-20275 and German Pat. No. 1,927,498, the movableslider of a variable resistor, set in the lens, is made variable ininterlocking with the distance ring of a photographic lens for a camera,so that the calculation is electrically performed by the electricresistance of said resistor; the result of the calculation beingindicated by the swing of the indicator of a meter to get the diaphragmvalue for a good exposure.

According to all of the above-mentioned prior arts, the combination ofdistance and diaphragm values is calculated and adjusted from the guidenumber of an auxiliary light in a special camera or lens, equipped witha calculation mechanism in the camera or the lens tube. Therefore, thecamera or lens has been so constructed as to be used for a specialmachine.

However, in order to equip such a calculation mechanism in a popularcamera, it is necessary to remodel the camera or lens essentially. Itwas substantially impossible to equip such a calculation mechanism in alens built-in type camera. In case of a camera, in which a lens tube anda camera body can be separated and interchangeable lenses, havingvarious kinds of open diaphragm values are used, it is impossible tomake it able to take a flash-light photograph with any of theinterchangeable lenses. The reason is that it is impossible to calculateexactly at the time of the automatic flash-light photographing, if theopen diaphragm values are not set the calculation mechanism for everykind of interchangeable lenses. There is such a defect that even if thecalculation mechanism is fitted to the camera body to receive an opendiaphragm value signal from the side of the interchangeable lens to beused, it is necessary to remodel both sides of the camera and the lensdrastically.

In case of a single-lens reflex camera, having interchangeable lensesused, when the distance ring of the interchangeable lens is adjusted, arange information is not transmitted as a mechanical displacement to theside of the camera body. Therefore, if the calculation mechanism iscontained only on the side of the camera body and the side of theinterchangeable lens is not remodelled, it cannot serve for theautomatic flash-light photographing. Both the camera and the lens mustbe substantially remodelled.

As above-mentioned, it is necessary for an existing camera to remodelthe camera and/or the lens substantially in order to take an automaticflash-light photograph. But such a remodelling is essentiallyimpossible. Therefore, a camera or lens must be specially constructedfor automatic flash-light photographing.

It is the object of the present invention to eliminate theabove-mentioned conventional defect and to provide a lens attachment,which is fitted additionally to the end of a lens so that it becomesable to take an automatic flash-light photograph.

Another object of the present invention is to provide a lens attachmentfor automatic flash-light photographing, comprising that a variableresistor is set in the attachment, fitted additionally to the end of thelens and said resistor is made variable in interlocking with theadjustment of the distance ring of the lens, so that the resistancevalue of said resistor can be caught as a range information.

The other objects of the present invention may be made clear from thedetailed description of embodiments of the present invention inreference to the attached drawings.

FIG. 1 is a perspective general view of a camera, when a lens attachmentaccording to the present invention is fitted to an interchangeable lenstype single-lens reflex camera;

FIG. 2, a perspective front view of a lens attachment;

FIG. 3, a perspective rear view of a lens attachment;

FIG. 4, a cross section view of the lens attachment, shown in FIGS. 1and 2;

FIG. 5, a partly sectional view of the lens attachment, shown in FIG. 3;

FIG. 6, a schematic view of the main part of a lens attachment accordingto the present invention;

FIGS. 7 and 8, respectively a side view and a front view of the mainpart of a lens tube, fitted with a lens attachment according to thepresent invention; and

FIG. 9, an assembly drawing for the main part of a lens attachmentaccording to the present invention.

DESCRIPTION OF EMBODIMENT

In FIG. 1, 1 is a single-lens reflex camera body; 2, a strobo, equippedto the accessary shoe, which is attached to the camera body 1; 3 aninterchangeable lens, attached to the camera body 1; 3₁, a diaphragmadjustment ring, equipped on the lens 3; 3₂, a range adjustment ring,equipped on the lens 3; 4, and attachment for automatic flash-lightphotographing; and 4₁, a lead connection of the attachment and connectedwith an outer terminal on the side of the camera body 1. The strobo 2 isso constructed that when the strobo 2 is fixed to the shoe 1, of thecamera, the leg 2, of the strobo is electrically connected with theconnecting terminal for a synchrocontact, equipped on the shoe 1₁.

When the lens attachment 4 according to the present invention is notfitted, the camera 1 is fitted a with the lens 3 and the strobo 2 toperform common strobo auxiliary light photographing. In this case, it isnecessary to figure out the diaphragm value from the guide number of thestrobo 2 and the distance, indicated by the distance ring 3₂ of the lens3. It is impossible to take the so called automatic flash-lightphotograph. If the attachment 4 is fitted to the end of the lens 3, itbecomes possible to take an automatic flash-light photograph asdescribed here-in-after.

The attachment 4 is shown in the detail in FIGS. 2 to 5. In eachdrawing, 5 is an attachment case, constructed in a channel shape andalso made so circular as to surround the end part of the lens tube,which will be explained below. 6 is a thumb nut, pivoted with a shaft 6,rotatably on the front face of the case 5 for adjusting the opendiaphragm value of the lens; and 6₂, a movable contact, fixed to theshaft 6₁. The diaphragm adjustment thumb nut 6 is, as shown in FIG. 2,so turned as to make the index correspond to each index diaphragmindication in order to be available for various lenses, having differentopen aperture values. It is loosely fixed by a click mechanism (notshown in the drawing). 7 is a bayonet plate, composed in one piece withthe case 5 and having notched portions 7₁, 7₂ and 7₃ to be inserted withbayonet claws as shown in FIG. 5. 9 is a confronting holder, made in onepiece with the case 1 and confronting the bayonet plate with a steppedportion, to leave a space 10 against said plate 7, so that the bayonetclaws on the lens side are inserted into the space to be held. 11 is arotary plate, made so circular as to cover the rear opening part of thecase 5 and having the peripheral edge held rotatably by fixing screws12₁, 12₂ and 12₃ on the bayonet plate 7. 11' is a covering plate for therotary plate 11. 13 is a distance ring holding member, inserted in aconcave groove 14 of the rotary plate 11 and held slidably in thedirection of the optical axis. It is bent in a L shape as shown in FIG.4 and has a slot 13₂ made on its bent part 13₁. The longitudinal lengthof the slot 13₂ should be such a sufficient length that when the pin ofthe distance ring of the lens is inserted in said slots as mentionedhereinafter, the pin is removed in the direction of the optical axisaccording to the degree of the lens to be drawn out, but the pin canfreely move in said slot 13₂ with a sufficient clearance.

15 is a check lever, having the end porition engaged with a notchedgroove 13₃, made on the side of the holding member 13 and besides,pivoted with a pivot journal 16, fixed to the rotary plate 11. When theattachment 4 is fitted to the lens tube, the interlocking pin on thedistance ring of the lens may be made to change in height, but the pincan be engaged or disengaged by this lever. 17 is a printed plate,contained in the case 5 and connected with the rotary plate 11 ininterlocking with an interlocking pin 18 as shown in FIG. 6. 19 is astationary contact, fixed through an isolated base plate 20 to theinside of the case 5 and always pressed to the printed plate 17. Asshown in the development of FIG. 9, the printed plate 17 is providedwith fixed resistors R₁ to R₁₀, firmly arranged in its circumferentialportion. Conductors C₁ to C₁₀ are printed in wiring for connecting therespective resistors successively in series with the adjoining.

Further, the conductors C₂₃, C₄₅, C₅₆, C₆₇, C₇₈, C₈₉ and C₉₁₀ areprinted in wiring in parallel to the respective conductors C₂ to C₉ withthe one-step displacement in a radial direction. Each conductor isstep-wise displaced in a radial direction in parallel to the conductorsC₃ to C₁₀, so that a conductive part is formed with a successive lag. Bythe rotation of the beforementioned open diaphragm value adjustmentthumb nut 6, the index is made to correspond to the diaphragm valueindex, stamped on the outer surface of the case 5. Then, the movablecontact 6₂ is removed by means of the shaft 6, to the position, shownwith a dotted line in FIG. 9, so that the position of the contact 6₂ isadjusted corresponding to the open diaphragm value of the lens. A fixedresistor, having an almost similar resistance value is available for therespective resistors R₁ to R₁₀. 21 is a clamp releasing lever, protrudedfrom the case 5 to be operated from outside and pressing a clamp lever22. 23 is a signal transmission cable, connected with the sliders 6₂ and19. FIGS. 7 and 8 are schematic views of the end portion of a lens tubewhich is applied with an attachment 4, having the abovementionedconstruction. In the drawings, .[.32.]. .Iadd.3₂ .Iaddend.is a distancering for adjustment of the range of a lens tube; .[.33.]. .Iadd.3₃.Iaddend., an interlocking pin, attached to the distance ring .[.32.]..Iadd.3₂ .Iaddend.; and .[.34.]. .Iadd.3₄ .Iaddend., an adaptor fixture,attached to the end of the lens tube and having a three-clawed bayonetpart .[.35.]. .Iadd.3₅ .Iaddend.. When the distance ring 1 is turned inthe direction of an arrow to adjust the range from the infinite distanceof the object to be snapped towards the near distance, the adaptorfixture juts straight out in the axial direction of the distance ring 1..[.36.]. .Iadd.3₆ .Iaddend.is a clamp groove, made in the bayonet part.[.35.]. .Iadd.3₅ .Iaddend..

The case that an attachment, constructed as above for automaticflash-light photographing, is fitted to a camera to take an automaticflash-light photograph, shall be explained as an example, as follows;

First, the bayonet 3₅ is inserted in the bayonet receiving grooves 7₁ to7₃ as the check lever 15 on the rotary plate 11 being pushed. Theattachment 4 is turned at a precribed angle to be mounted on theuniversal lens tube, having the interlocking pin .[.33.]. .Iadd.3₃.Iaddend. in the distance ring .[.32.]. .Iadd.3₂.Iaddend.. The lens tube3 and the attachment 4 are firmly fixed by the respective bayonet parts35 and 7, and clamp 22 and the clamp groove 36, and a spring (not shownin the drawing), which acts on the clamp 22. Next, the check lever 15 ispushed to release the L-shaped member 13 in a diametrical direction fromthe engagement with the interlocking pin 33. In this condition, theinterlocking pin .[.33.]. .Iadd.3₃ .Iaddend. of the distance ring.[.32.]. .Iadd.3₂ .Iaddend. is fitted to the long groove 13₂ of theL-shaped member 13, and the check lever 15 is released from pushing.Then, the L-shaped member 15 is restored to be engaged with theinterlocking pin 3₂, because the spring is acting to the check lever 15.Thus, the distance ring 3₂ of the lens tube is interlocked with therotary plate 11 of the adaptor. The click operation of the opendiaphragm value adjustment thumb nut 6 can be selectively applied toseveral kinds of lenses, having a different focal distance and opendiaphragm value. Therefore, it is set to the lens tube 3, interlockingwith the attachment 4. Finally, the cord 23, having two terminals of amovable contact 6₂ and a contact brush 19, is connected in parallel withCdS of the exposure control circuit 21 of the camera through achange-over switch Sw. In order to equip the attachment 4, the body ofthe attachment 4 is turned at a certain angle, as the clamp push button21 and the check lever 15 being pushed.

In case of flash-light photographing, the switch SW is changed over fromthe contact a of the exposure meter circuit to the contact b of theflash circuit (FIG. 5). Then, the guide number is set and the distancering 1 of the tube is operated. When the range is adjusted to the objectto be snapped, the printed plate 17 is rotated by the rotary plate 11and the fixing pin 18. The resistance value inside the attachment ismade to change corresponding to the distance. The diaphragm value isautomatically calculated. In the needle-type camera, the needle is setto the diaphragm control device of the lens tube, so that the irisaperture is determined, while in the EE camera, the iris aperture isdetermined at the same time when the diaphragm value is calculated bythe EE mechanism. .Iadd.The ammeter and the diaphragm control device maybe referred to as electrical means, and the CdS element as a photometricelement. Together these form part of what is referred to as diaphragmcontrol means. .Iaddend.

When light is measured in a camera of the so-called TTL open exposuremeasuring system, attached with a kind of lens, having different open Fnumbers, the ammeter deflects at a different angle, as a result of thedifference of the passing quantity of light, even though the same objectis snapped. Accordingly, in this type of camera, the ammeter is turned(absolute value signal type) or the diaphragm index of the finder ismoved (system of open F numbers being evenly arranged) by a mechanicalor manual operation for compensation. .Iadd.The term correcting means isapplied hereafter to the apparatus performing this compensation. Thecorrecting means in combination with the diaphragm control device can bereferred to as operating means. .Iaddend.It is necessary to change overexactly for the above-mentioned compensation on the camera side in caseof flash-light photographing, because the diaphragm value for thedistance from the object to be snapped must be always same withoutregard to the open F number of the lens.

In the apparatus according to the present invention, the change-overeffect is obtained for the difference of the open F number of the lens,by that the conductors (C₁ to C₁₀) and (C₂₃ to C₉₁₀) are placed on theprinted plate 17 with a lag for a series of resistance values accordingto the distance from the object to be snapped. For example, as shown inFIG. 9, the F 2 lens has a larger resistance value by one step at thesame distance of 2 m from the object to be snapped, as compared with the.[.F 1,4.]. .Iadd.F 1.4 .Iaddend.lens, having the same focal distance.The resistance value corresponds to that of the camera, having a .[.F1,4.]. .Iadd.F 1.4 .Iaddend.lens, at the distance of 2.8 m from theobject to be snapped. Similarly, the resistance value of a F 2.8 lens,having another focal distance, is large by two steps and corresponds tothat of a F 1.4 lens at the distance of 4 m.

As the present invention is composed as above, flash interlocking orautomatic flash photographing can be performed for a plurality ofcameras, having the same indication current value of an exposure meter,in combination of a plurality of lens, having different focal distanceand open diaphragm values. The simplification and automation of flashphotographing as well as the enlargement of a flash photographic rangeare also resulted very conveniently. .Iadd.The members 19 and 17 are apart of what may be referred to as information setting means while theterm selector means may be used to refer to the switch SW. The membersC₁₀ to C₈₉ and the member 6₂ may be referred to as removing means,defeat means, and recorrecting means. However, the various "means" termsbefore and hereafter are not limited to the particular elementmentioned. The members 19, C_(o) to C₈₉, and 6₂ may be referred tocollectively as resistance varying means. The members 3₂, 3₁, and the(unnumbered) shutter time setter may be collectively referred to as dataentering means, while the term sensing means may include the elementCdS. The term coupling or connector or interconnecting means may be usedto include the member 13₂, and the bayonet plate 7 may be referred to asmounting means.

What is claimed:
 1. For an automatic flash camera having an automaticdiaphragm control and a photographic lens with a rotatable focusingring, a lens attachment, comprising mounting means for detachablymounting the attachment at the end of the lens, interconnecting meansrotatably mounted on said mounting means and engageable with thefocusing ring, variable resistance means mounted on said mounting meansand said interconnecting means, said resistance means being variable bymovement of said interconnecting means with the focusing ring and havingan adjustable member which is movable between a plurality of positions,said variable resistance means exhibiting one range of resistancescorresponding to one type of lens when the member is in one position andthe interconnecting means is moved relative to the mounting meansthrough a given path, said variable resistance means exhibiting anotherrange of resistances corresponding to another type of lens when themember is in another position and the interconnecting means is movedrelative to the mounting means through a path corresponding to the onepath, electrical means connected with said variable resistance means andcoupled to said diaphragm control means for adjusting the diaphragm onthe basis of an electrical resistance value based upon the rotation ofthe focusing ring and the position of said member, said member beingadjustable to a position causing said resistance means to exhibit arange of values corresponding to the type of lens.
 2. An attachment asin claim 1, wherein said variable resistance means includes a pluralityof conductive contact means extending along a plurality of separatepaths and mounted on one of said interconnecting means and said mountingmeans, said resistance means further including a slider mounted on theother of said mounting means and said interconnecting means andcontacting one of said contact means on the basis of the position ofsaid member and movable along one of the paths when said interconnectingmeans moves with respect to said mounting means and varying theresistance exhibited by said resistance means on the basis of the typeof lens being used and the position of the focusing ring.
 3. Anattachment as in claim 1, wherein said variable resistance means extendsalong a circular path.
 4. A system as in claim 2, wherein said resistormeans extend along circular paths.
 5. An attachment as in claim 2,wherein each of said contact means comprises an insulating base plate, aplurality of contact strips extending along the path, said strips beingseparated from each other, a plurality of resistances connected betweensaid contact strips, the location of said contact strips causing saidslider to be connected to different ones of said resistances dependingupon the position of said member and the focusing of said ring, andwiring means connecting said resistance means to said circuit means. 6.A camera, comprising a camera body, an interchangeable lens, anadjustable focusing ring on the lens, mounting means for detachablymounting the attachment at the end of the lens, interconnecting meansrotatably mounted on said mounting means and engageable with thefocusing ring, variable resistance means mounted on said mounting meansand said interconnecting means, said resistance means being variable bymovement of said interconnecting means with the focusing ring and havingan adjustable member which is movable between a plurality of positions,said variable resistance means exhibiting one range of resistancescorresponding to one type of lens with the members in one position andthe interconnecting means is moved relative to the mounting means, saidvariable resistance means exhibiting another range of resistancescorresponding to another type of lens when the member is in anotherposition and the interconnecting means is moved relative to the mountingmeans, electrical means connected with said variable resistance meansand coupled to said diaphragm control means for adjusting the diaphragmon the basis of an electrical resistance value based upon the rotationof the focusing ring and the position of said member, said member beingadjustable to a position cause said resistance means to exhibit a rangeof values corresponding to the type of lens.
 7. A camera as in claim 6,wherein said variable resistance means includes a plurality ofconductive contact means extending along a plurality of separate pathsand mounted on one of said interconnecting means and said mountingmeans, said resistance means further including a slider mounted on theother of said mounting means and said interconnecting means andcontacting one of said contact means on the basis of the position ofsaid member and movable along one of the paths when said interconnectingmeans moves with respect to said mounting means so as to vary theresistance exhibited by said resistance means on the basis of the typeof lens being used and the position of the focusing ring.
 8. A camera asin claim 6, wherein said variable resistance means extends along acircular path.
 9. A system as in claim 7, wherein said resistor meansextend along circular paths.
 10. A camera as in claim 7, wherein each ofsaid resistor means comprises an insulating base plate, a plurality ofcontact strips extending along the path, said strips being separatedfrom each other, a plurality of resistances connected between saidcontact strips, the location of said contact strips causing said sliderto be connected to different ones of said resistances depending upon theposition of said member and the focusing of said ring, and wiring meansconnecting said resistance means to said electrical means. .Iadd. 11.For a single lens reflex camera having an interchangeable lens with amaximum diaphragm aperture, diaphragm control means including electricalmeans and a photometric element coupleable to said electrical means forreceiving light passing through the maximum aperture of theinterchangeable lens, and correcting means for correcting variations inthe measurements of the photometric element as a result of theparticular maximum aperture of the interchangeable lens, an automaticflash control device comprising:information setting means connectable tothe diaphragm control means for setting information for flashphotography, selector means for connecting said electrical means to oneof the photometric elements and the information setting means independence upon whether the flash is to be used, and removing means insaid setting means for substantially removing the correction of thecorrecting means. .Iaddend. .Iadd.
 12. An apparatus as in claim 11,wherein said setting means forms a part of an attachment removablymounted on said interchangeable lens, said setting means includingvariable resistance means connectable to said electrical means, saidresistance means exhibiting an output resistance and having firstresistance varying means for varying the resistance on the basis ofmanually entered flash information and second varying means for varyingthe resistance on the basis of the maximum aperture of the lens..Iaddend..Iadd.
 13. An automatic flash device for a single lens reflexcamera having an interchangeable lens, a diaphragm control meansincluding electrical means connectable to a photometric element whichreceives light passing through the full-opened diaphragm of theinterchangeable lens, and a means for correcting errors in thephotometry corresponding to the open diaphragm value of theinterchangeable lens, said automatic flash photographing meanscomprising: setting means connectable to the diaphragm control means forsetting information for the flash photography selector means forchanging and connecting the photometric element and the informationsetting means to the electrical means in correspondence to daylightphotography and flash photography, and means for substantially removingthe correction corresponding to the open diaphragm value of theinterchange lens for the flash photography. .Iaddend. .Iadd.
 14. Thedevice according to claim 13 wherein said setting means form part of anattachment removably mounted on one end of the interchangeable lens,said attachment comprising a variable resistance means for setting theflash photography information, connectable to the electrical means andvarying means for changing the correction made according to the opendiaphragm value of the interchange lens correctly for performing a flashoperation. .Iaddend..Iadd.
 15. The device according to claim 14 in whichthe varying means includes a variable resistance and a contact means..Iaddend. .Iadd.
 16. The device according to claim 13 in which theelectrical means includes an ammeter, and the correction means rotatesthe ammeter in correspondence to the open diaphragm value of theinterchangeable lens. .Iaddend..Iadd.
 17. An automatic flash device fora single lens reflex camera having an interchangeable lens, diaphragmcontrol means including electrical means connectable to a photometricelement which receives light passing through the full-opened diaphragmof the interchange lens, and means for correcting errors in thephotometry corresponding to the open diaphragm value of the interchangelens, said automatic flash photographing device comprising: informationsetting means for setting information for flash operation, connectableto the diaphragm control means, a selector means for connecting thephotometric element and the information setting means to the electricalmeans in correspondence to daylight photographing and flashphotographing, and a recorrecting means for recorrecting the previouslymade correction on the basis of the open diaphragm value of theinterchangeable lens when the selector means is set for performing flashphotography. .Iaddend..Iadd.
 18. The device according to claim 17,wherein said setting means and recorrecting means form part of anattachment removably mounted on one end of the interchange lens..Iaddend..Iadd.
 19. For a single lens reflex camera with a body and oneof a plurality of interchangeable lenses having a plurality of maximumapertures, a plurality of data entering means on at least one of saidbody and said lens, sensing means for sensing through the maximumaperture of the lens, operating means responsive to the maximum apertureof the lens and coupled to said sensing means for establishing at leastan indication of the aperture to which the lens is to be set on thebasis of said sensing means and varying it on the basis of the maximumaperture of the lens, a flash adjusting device, comprising: settingmeans responsive to one of said entering means and coupleable to saidoperating means for constraining said operating means to establish anaperture; switch means for disconnecting said sensing means from saidoperating means and connecting said setting means to said operatingmeans; said setting means including defeat means for defeating thevariation in the aperture produced by said operating means in responseto the changes in the maximum aperture of the lens. .Iaddend. .Iadd. 20.An apparatus as in claim 19, wherein said defeat means includes aplurality of resistance means and means for varying the resistance onthe basis of the maximum aperture of the lens. .Iaddend..Iadd.
 21. Anapparatus as in claim 19, wherein said operating means includes anammeter, and said ammeter is rotated on the basis of the maximumaperture of the lens. .Iaddend. .Iadd.
 22. An apparatus as in claim 19,wherein said setting means includes an attachment removably mounted onone end of said interchangeable lens, said attachment including couplingmeans coupled to said entering means, and means for setting said defeatmeans to a particular setting corresponding to the maximum aperture tobe defeated. .Iaddend..Iadd.
 23. An apparatus as in claim 19, whereinsaid entering means is the focusing ring. .Iaddend. .Iadd.
 24. Anapparatus for adjusting the operation of an interchangeable-lensfocus-adjustable single-lens-reflex flash camera, comprising settingmeans for establishing an aperture value on the basis of flashinformation, connector means for entering the information, said settingmeans including varying means for varying the flash information on thebasis of the maximum aperture of the interchangeable lens being used..Iaddend..Iadd.
 25. A camera comprising a body, one of a plurality ofinterchangeable lenses having one of a plurality of maximum apertures, aplurality of entering means for entering information into said camera,sensing means in the path of light from the lens for producing an outputresponding to light striking the sensing means, control means responsiveto said sensing means for establishing a value corresponding to thedesired ambient-light aperture of the lens, setting means coupled to oneof said entering means for setting a value corresponding to a desiredflash aperture, a switching means for disconnecting said sensing meansfor said control means and connecting said setting means to said controlmeans, said setting means having variable defeat means settable to aplurality of positions corresponding to one of the plurality of maximumapertures for varying the set value on the basis of the maximum apertureof the lens. .Iaddend.